In the manufacture of various items such as automobile bodies, it is common to utilize portable seam welders along a production line to weld various parts on the body. One commonly used type of portable seam welder comprises welding wheels mounted on shafts which extend generally along the longitudinal axis of the arms which are pivoted to one another. One of the problems with respect to such welders is that because of the size and construction, they are difficult to handle. In addition, radial roller bearings are used as load carrying members as well as electrical contact members; this results in a relatively low contact area and burning of the contact rollers on the opposite side of spindle pressure which reduces the life of said bearings and the amount of current flowing to the weld wheels. Further because of the difficulty of providing enough current, they operate at low speed and commonly provide longitudinally spaced spot welds rather than a continuous seam weld.
Although large high capacity stationary welders have been known, as far as I am aware, no portable welders have been developed which provide a continuous seam of any reasonable duration in a portable seam welder.
In addition, it is difficult to adjust the rolls angularly with respect to one another to provide clearance for various product configurations.
Accordingly, among the objects of the invention are to provide a portable seam welder which can be readily handled, which produces a continuous seam weld, which is readily adjustable, which can be changed from right to left hand use, which produces a uniform speed of weld; and wherein either one or both of the rollers may be driven and in which the current carrying collector ring assembly is separate from the spindle radial and thrust support bearings.